Garbage-rubbish incineration process



y 30, 1939- G. w; KELLEY. JR' 7 2,160,699

GARBAGE-RUBBISH INCINERATION PROCESS Filed Nov. 3, 1954 Patented May 30, 1939 GARBAGE -RUBBI SH INCINE RATION PROCESS George W. Kelley, Jr., Philadelphia, Pa., assignor of one-half to Archer M. Soby, Overbrook, Pa.

Application November 3, 1934, Serial No. 751,386

6 Claims.

My invention relates to improvements in garbage disposal systems, and the principal object of the invention is to provide a process of garbage disposal that by reason of its characteristics of relative simplicity, rapidity, safety and economy shall be better adapted to the requirements of the average municipality than the prior available processes.

The complete reduction process of garbage dis- H) 'posal, if carefully and efficiently conducted, is highly economical, but this process is relatively complicated and for satisfactory results requires the services of an expert. This process, if not expertly conducted, may be both costly and dangerous and may constitute a great sanitary nuisance. It is, therefore, not a practical method of garbage disposal for the average municipality, as has been proved by the experience of some of the largest municipalities where this method of garbage disposal has been employed.

The straight incineration method of garbage disposal has the advantage of relative simplicity, is sanitary, and is, therefore, well adapted for use by the average municipality, but the costof operation is high, since it entirely lacks the ad-- vantage of the recovery of salable byproducts which is the economical feature of the reduction method. In spite of its high cost of operation,

, .the incineration method of disposal for the reasons set forth above is the one now almost universally employed.

More specifically, an object of the present invention is to provide a process of garbage disposal which while avoiding the complication and other major disadvantages of the complete reduction system shall still partake to a; substantial degree of its. economy and which shall be readily adaptable atlow cost to established incineration plants both for the purpose of substantially increasing the capacities of said plants and for materially reducing their cost of operation. The invention fmtheraffords a simple and relatively economical system of garbage disposal the operation of which is well within the technical capacity of municipalities of any order., g

The invention further resides inthe novel apparatus hereinafter described and illustrated in perspective in the attached drawing.

. The process will be readily understood by reference to the drawing, wherein green garbage is shown being deposited from a truck I onto a conveyer 2 which carries the garbage to digesters 3, 3. By direct application of steam to the digesters 3, the garbage is disintegrated and the fats rendered, and the vapors are discharged from the digesters into a jet or barometric condenser 4, which condenser is connected to a sewerv or other suitable drain. In the present instance, steam is introduced to the digesters 3,'

3 through a, pipe 5 having branches 6, 6 which enter the bottoms of the digesters at diametrically opposite sides thereof, as ilustrated. With a digester of approximately eight tons capacity and filled with garbage, I have found that the application of steam as described for a period of two to three hours produces the desired degree of reduction.

From the digesters the rendered garbage is discharged by gravity to an enclosed hopper tank l which is vented to a jet or barometric condenser 8, which like the condenser 4 may be connected to a sewer or other suitable drain. From the hopper i the rendered garbage passes by gravity to a press 9 of the screw, hydraulic, roller or other suitable type, and in this press the moisture and fats are partially extracted from the garbage and are accumulated in a sump Ill, from which sump the extracted liquids are conducted through a pipe H and by means of a H suitable pump I2 to a tank l3. In the tank I3, the fats are permitted to rise to the top of the liquid column and are thus separated from the waste liquids which remain at the bottom. The

waste liquids are drawn off through the valve 1 l3a and are passed to the sewer, leaving the usable fats, containing suspended solids, in the tank. The fats and suspended solids are then passed through the valve l3b to a curb or othersuitable press 14 which functions to separate present instance, I provide a conveyer I? which receives the press cake from the-presses 9 and I4 and carries it to thefurnace H5. The press cake produced as described can be burned on the incinerator grate without additional fuel, or it can be applied to the incinerator in conjunction with rubbish, in which case due to the B. t. u. value of the press cake it materially assists in the reduction of combustible rubbish to ash.

The gases resulting from the burning of the press cake either alone or combined with those of combustible rubbish are introduced into a waste heat boiler I 8 to generate steam which may be used in the operation of the digesters, presses and pumps. In the present instance, I have illustrated the steam supply pipe of the digesters 3 extending to the boiler l8.

I have found that the dehydrated garbage or press cake resulting from the process described above may be reduced to ash in the incinerator furnace in at least one-fourth of the time required for disposition of its equivalent in green garbage under corresponding furnace conditions,

and I have demonstrated that in operation four to six times as much garbage can be disposed of in an incinerator furnace by my process than by any other known method. By combining features of reduction and incineration-as described above, I not only provide a process of disposal which is materially faster than the garbage disposal processes heretofore practiced, but one which is relatively economical not only by reason of the recovery of salable components but also by reason of the ability to utilize relatively inexpensive apparatus operated at least in part by the products of combustion of the highly combustible rendered garbage. V

.In the above described process, the reduction operations, by reason of the profit derived from sale of the recovered greases and the use of the steam generated by the incinerating operation, may be conducted, even at the present relatively low market value for the byproduct, without cost, and wider more normal conditions at a substantial profit. The cost of operating the incinerator on the other hand as compared with the cost of operation when disposing of green garbage is materially reduced. This economy in incinerator operation is due to the concentrated character of the rendered garbage received from the reduction operation, the highly combustible character of this garbage and its relatively low moisture content, the definite fuel value of the concentrated garbage which makes possible its reduction to ash without added fuel or combustible material, and the-elimination from the garbage of a substantial proportion of its originally solid components in the form of soluble salts eliminated during the reduction operation. Specifically the cost of the incinerator operation is reduced to approximately one-third of the cost of operation of the incinerator in a straight incineration process. It is apparent, therefore, that even under present conditions my process affords a substantial economy over the operation of incinerator systems as now conducted, and that under conditions affording a more normal profit from the salable byproducts of the reduction operation, the operation costs of the system as a whole will be reduced to an even greater degree. It is believed that the process constitutes the most economical universally practicable method of garbage disposal yet devised.

I claim:

1. In the disposal of municipal refuse inclusive of garbage and rubbish, the process which consists in disintegrating the green garbage by heat, extracting free water and fats and entrained solids from the rendered garbage by pressure with the production of a press cake of a combustible solid residue of high fuel value, segregating the extracted fats and entrained solids, separating the said fats from the entrained solids by pressure with the production in the resulting press cake of an additional solid fuel residue,

utilizing said residues as a fuel for eificient incineration of said rubbish, generating steam with the heat of said incineration, and employing said steam in the said disintegrating process.

2. In the disposal of municipal refuse inclusive of garbage and rubbish, the process which consists in disintegrating the green garbage by heat, extracting free water and fats and entrained solids from the rendered. garbage by pressure with the production of a press cake of a combustible solid residue of high fuel value, segregating the extracted fats and entrained solids, and separating the said fats from the entrained solids by pressure with the production in the resulting press cake of an additional solid fuel residue, said residues by reason of their high fuel value being adapted for use in the efflcient incineration of said rubbish and for generation of steam employable in the disintegration of the green garbage.

3. A self-sustaining process of garbage disposal, which comprises disintegrating the green garbage by heat, extracting free water and fats and entrained solids from the rendered garbage by pressure with the production of a press cake of a combustible solid residue of high fuel value, segregating the extracted fats and entrained solids, separating the said fats from the entrained solids by pressure with the production in the resulting press cake of an additional solid fuelresidue, said residues having a fuel value in excess of that required for generating the steam and heat requirements of said disintegrating process, and utilizing said residues as -a fuel for generating said steam and heat.

4. In apparatus for the disposal of municipal refuse inclusive of garbage, and rubbish, the combination with a steam-heated container adapted to receive the green garbage and in which said garbage is disintegrated by the action of said steam, of a press arrangedto receive the disintegrated garbage from said container and to extract from said garbage free water and fats and entrained solids with the production of a press cake of a combustible solid residue of high fuel value, a container for reception of said extracted water and fats, and means for passing said water and fats to the container, means for drawing off the water from the bottom of said container to thereby segregate the fats with their entrained solids, a second press arranged to receive said segregated fats and to separate the fats from said entrained solids with the production in the press cake of additional solid residue of fuel value, a furnace for incineration of the said rubbish and of said solid residues, means associated with said furnace for utilizing the heat of said incineration for generation of steam, and means for conducting the steam to said container for disintegration of the garbage.

5. A process for disposal of municipal refuse, inclusive of garbage and rubbish, which comprises disintegrating green garbage by heat, expressing free water, fats and entrained solids from the rendered garbage with the production of a combustible solid garbage residue of high fuel value, freeing said fats from the entrained solids with recovery of the fats in salable form and with the production of additional combustible residue to augment the residue first named, said residues having in themselves sufficient fuel value to supply the heat required 'for said disintegration, utilizing said residues as a fuel for generating said heat and for efficient incineration of said rubbish, generating steam with the heat of said incineration, and employing said steam in the said disintegration process, said disposal process being independent of fuel from sources extraneous to said refuse.

6. An economically self-sustaining process for disposal of garbage, which consists in disintegrating green garbage by heat, expressing free water, fats and entrained solids from the rendered garbage with the production of a combustible solid garbage residue of high fuel value, freeing said fats from the entrained solids with recovery of the fats in salable form and with the production of an additional combustible residue to augment the residue first named, said residues having in themselves sufiicient fuel value to supply the heat required for said disintegration, utilizing said residues as a fuel for generating steam, and employing said steam in the disintegration process, said disposal process being independent of fuel from sources extraneous to said garbage.

GEORGE W. KELLEY, JR. 

